Wildlife Directory

Virginia Opossum
( Didelphis virginiana )

The opossum (Didelphis virginiana) can be identified by the grizzled white fur, small, dark ears, and long, furless tail.
Photo courtesy of the Forest Preserve District of Dupage County.

Did you know?

The opossum is the only marsupial (carries its young in a pouch) in North America.

Opossums have 50 teeth; the most teeth of any North American mammal.

Opossums have prehensile tails, which allows them to hang upside down by
their tail. However, they can only hang by their tail for a short time.

Description and Identification

Opossums belong to the Didelphidae family (New World Opossums). Adults are the
size of an average house cat, weighing six to 15 pounds, and are 24 to 33 inches
in length (body and tail). Males are typically larger than females. Opossums have
white fur tipped with gray or black and white guard hairs. They have a long,
narrow snout, pink nose, and bare ears. The inner side of the ear is black. Their
tails are nearly as long as their body and are almost hairless. Because their ears
and tails lack fur they often suffer frostbite on these body parts during
Illinois' winters.

Tracks

Opossums have five toes on each foot similar to raccoons. However, it is easy
to distinguish opossum tracks from raccoon tracks. An opossum's rear tracks
resemble a baby's handprint. This is because the inner toe on each hind foot is
opposable, lacks a claw, and resembles a thumb. An opossum's front and rear tracks
are usually close together, with the rear track falling on top of or just behind
the front track. If the animal is moving slowly a tail drag mark may be
noticeable, but an opossum typical holds its tail off the ground when walking.

Droppings

The droppings of an opossum are approximately two to two and a half inches long
and are irregularly shaped. Pieces of fruit hulls, seeds, feathers or fur are
often visible in the droppings.

Habitat

Opossums live in or near wooded areas, especially those near water. They are
adapted to edge habitats and are often found in urban areas. Opossums do not build
their own shelters. They take cover in abandoned dens or nests of other animals,
sheds or old buildings, cavities in rocks, brush piles, and hollow trees or fallen
logs. Home ranges of 12 to 264 acres have been reported.

Distribution and Abundance

Opossums are common throughout Illinois. They are more abundant in the southern
part of the state, especially along the Wabash, Mississippi, and Ohio rivers. A
study of opossums in central Illinois estimated there were 300 opossums per square
mile during mid-summer. Opossums are most abundant in midsummer. However, many
opossums do not survive their first year and the population drops by late
winter.

Reproduction

Opossums breed in late January and early February with some individuals
breeding again in May. Females have one to two litters per year. The average
litter size is seven to eight young. The female gives birth to underdeveloped
young approximately 13 days after mating. At this stage, the young are about the
size of a bumblebee and they must crawl to their mother's pouch where they
continue to develop. Young opossums leave the pouch when they are two to three
months old but remain near the female so that they can return to her pouch to
nurse. During this stage of their life, they may be seen riding around on the
female's back. By the time they are three months old, they will be weaned and on
their own.

Food

Opossums are omnivorous scavengers. They eat insects, fruits and berries,
earthworms, bird eggs, amphibians, and green vegetation. However, the main
component of their diet is carrion. Opossums are often killed by vehicles while
scavenging for carcasses along roads.

Behavior

Opossums are nocturnal (active at night). They are solitary animals except
while females are raising young. Opossums are generally shy and passive. When an
opossum is threatened, it will stand still, bare its teeth, and hiss or growl. If
the defensive posturing is ineffective, or if the opossum is attacked, it may
pretend to be dead. This defensive mechanism is similar to fainting and is
commonly known as "playing possum."

Longevity

Opossums have many predators including dogs, great horned owls, coyotes, foxes,
raccoons, bobcats, raptors, and snakes. Many are also killed each year by
vehicles. The average opossum lifespan is two years.

Damage Prevention and Control Measures

Opossums are most likely to cause problems by getting into garbage or raiding
bird feeders. Though they do not usually cause damage, they can startle people
when they take shelter in woodpiles, sheds, under decks and porches, or in other
unexpected places.

Habitat Modification

Do not leave pet food outside overnight.

Remove spilled bird seed.

Remove brush or trash piles.

Store firewood away from buildings or fences and keep the wood at least a foot off of the ground.

Exclusion

Close garbage dumpster lids each night to prevent opossums from climbing or falling into the dumpster.

Regularly check your home for signs that it needs repair and make the repairs quickly.

Repair loose fascia boards.

Check the integrity of chimney caps and attic vents, and repair any holes.

Deny access to sheds or to spaces underneath decks or porches. For porches
or decks built within two feet of the ground, dig a trench at least 10 inches
deep around the deck's perimeter. Attach ½" × ½" mesh hardware cloth or 1" ×
1" welded wire from the top of the outside joists to the bottom of the trench.
Leave six to eight inches of wire at the bottom and bend it out at a 90°
angle. Fill the trench with soil or rocks. Add lattice or other cover for
aesthetics.

Removal

Habitat modification and exclusion techniques are usually sufficient to prevent
problems with opossums. If there is a situation that warrants removal, you can
call a nuisance wildlife control operator to trap
and remove the opossum for you for a fee. If you want to remove the opossum
yourself you will need to call the Illinois Department of Natural Resources
District Wildlife Biologist assigned to your
county to request an animal removal permit. Opossums must be live-trapped and
either released alive on your property, or elsewhere with the landowner's
permission, or surrendered to a licensed rehabilitator.

Opossums can easily be trapped at night using a Tomahawk trap baited with cat
food. If the opossum is to be released on property other than the site where it
was captured, prior written permission must be obtained from the landowner.
Opossums must be relocated into suitable habitat within 24 hours of capture. If
the opossum will not be released onto the property where it was captured, it must
be released at least 10 but not more than 40 miles from the capture site unless
the IDNR biologist specifies otherwise.

Public Health Concerns

Opossums are not a public health concern. They are often infected by parasites,
but there are no known risks to humans. Opossums have a resistance to rabies but
may still be carriers of the disease.

Horse owners should be aware that opossums can be carriers of a protozoan,
Sarcocystis neurona, that can cause Equine protozoal
myeloencephalitis (EPM), a degenerative neurological disease of the central
nervous system that affects horses. Horses can become infected when they consume
feed or water that has been contaminated by opossum feces containing the protozoan
sporocysts. Not all infected horses will show symptoms, but those that do will
require long-term, expensive treatment. To prevent possible transmission make sure
the feed and water sources used by horses cannot be reached by opossums.

Ecological Role

Opossums are the only marsupial in North America. They are mesopredators, like
raccoons and skunks, and help control insect, small mammal and bird populations.
Since they are omnivores, they also play a role as seed disperers. As scavengers
they help reduce the number of carcasses in their home range. Finally, opossums
are an important source of food for predators such as owls and raptors, coyotes
and foxes, raccoons, and bobcats.

Legal Status

In Illinois, opossums are protected by law as a furbearer. In urban areas,
opossums that become nuisance animals may be trapped and removed if an animal
removal permit is issued by an Illinois Department of Natural Resources
District Wildlife Biologist. In rural areas, a
hunting or trapping license is needed to harvest an opossum. There is no limit to
the number of opossums an individual with a hunting or trapping license may take
during season. Opossums may be hunted or trapped November through mid-February
except during firearm deer hunting season and trapped from November through
January. For full regulations, visit the
IDNR Licenses &
Hunting website.